Gynaecological malignancies and sentinel lymph node mapping: an update

Value of sentinel node ultrastaging and pathologic techniques in tumoral detection

PURPOSE OF REVIEW

Sentinel lymph node assessment is an option for patients with clinically early-stage vulvar cancer, endometrial cancer, cervical cancer, and, more recently, ovarian cancer. However, although ultrastaging is mandatory as part of the node evaluation, universally accepted pathology protocols are lacking. This review focuses on the current evidence for the most relevant aspects of sentinel lymph node evaluation, as well as some controversial topics like frozen section or one-step nucleic acid amplification.

RECENT FINDINGS

The diagnostic accuracy of sentinel lymph node detection algorithms for patients with gynecologic neoplasms is high. However, the heterogeneity among the published studies and the absence of clear recommendations from most guidelines make it challenging to recommend one protocol over another. The minimum requirement from ultrastaging protocols (regarding the number of levels to be assessed, among others) to get the highest accuracy with a minor cost is unknown.

SUMMARY

Sentinel lymph node evaluation is now part of the surgical management for most early-stage gynecologic neoplasms. However, a universally accepted ultrastaging pathology protocol is lacking in literature and clinical practice. This gap requires significant effort from the gynecologic oncology and pathology community to be closed and then to allow advancements in surgical management for early-stage gynecologic tumors to go forward.

Establishing guidelines for sentinel lymph node ultrastaging in endometrial cancer

BACKGROUND

Many sentinel lymph node (SLN) ultrastaging protocols for endometrial cancer exist, but there is no consensus method.

OBJECTIVE

This study aims to develop guidelines for size criteria in SLN evaluation for endometrial cancer, to determine whether a single cytokeratin AE1:AE3 immunohistochemical slide provides sufficient data for diagnosis, and to compare cost efficiency between current and limited ultrastaging protocols at a large tertiary care institution.

METHODS

Our current SLN ultrastaging protocol consists of cutting two adjacent paraffin block sections at two levels (L1 and L2), 50 μm apart, with two slides at each level stained with hematoxylin and eosin and cytokeratin AE1:AE3 immunohistochemistry. We retrospectively reviewed digitized L1 and L2 slides of all positive ultrastaged SLNs from patients treated for endometrial cancer between January 2013 and January 2020. SLN diagnosis was defined by measuring the largest cluster of contiguous tumor cells in a single cross section: macrometastasis (>2.0 mm), micrometastasis (>0.2 to ≤2.0 mm or >200 cells), or isolated tumor cells (≤0.2 mm or ≤200 cells). Concordance between L1 and L2 results was evaluated. Cost efficiency between current (two immunohistochemical slides per block) and proposed limited (one immunohistochemical slide per block) protocols was compared.

RESULTS

Digitized slides of 147 positive SLNs from 109 patients were reviewed; 4.1% of SLNs were reclassified based on refined size criteria. Complete concordance between L1 and L2 interpretations was seen in 91.8% of SLNs. A false-negative rate of 0%-0.9% in detecting micrometastasis and macrometastasis using a limited protocol was observed. Estimated charge-level savings of a limited protocol were 50% per patient.

CONCLUSION

High diagnostic accuracy in SLN interpretation may be achieved using a limited ultrastaging protocol of one immunohistochemical slide per block and linear measurement of the largest cluster of contiguous tumor cells. Implementation of the proposed limited ultrastaging protocol may result in laboratory cost savings with minimal impact on health outcomes.

Clinical relevance of sentinel lymph node biopsy in early ovarian cancer

The first-line treatment for early ovarian cancer typically involves primary debulking surgery aimed at maximal cytoreduction, alongside adjuvant chemotherapy if clinically indicated. Nodal assessment involving pelvic and para-aortic lymph node dissection is typically performed during the primary debulking surgery. However, the survival benefit of lymphadenectomy in patients with early ovarian cancer has not been well established, and the procedure is associated with longer operation time and higher perioperative complications. With the emergence of minimally invasive surgery as a potential alternative to laparotomy for early ovarian cancer, sentinel lymph node biopsy has been evaluated in this setting. In this review, we summarized the current literature regarding sentinel lymph node biopsy in patients with early ovarian cancer, focusing on the clinical relevance of this method, including its detection rate and diagnostic accuracy. Additionally, we discuss the current status of clinical trials investigating sentinel lymph node biopsy in early ovarian cancer cases.

Prognostic Significance of Size, Location, and Number of Lymph Node Metastases in Endometrial Carcinoma

Regional lymph node metastasis is a well-established negative predictive prognostic factor in endometrial carcinomas. Recently, our approach to the pathologic evaluation of lymph nodes in endometrial carcinomas has changed, mainly due to the utilization of immunohistochemical stains in the assessment of sentinel lymph nodes, which may result in the identification of previously unrecognized disease [particularly isolated tumor cells (ITCs)] on hematoxylin and eosin stained slides. However, the clinical significance of this finding is not entirely clear. Following the experience in other organs systems such as breast, the Eight Edition of the American Joint Committee on Cancer's Cancer Staging Manual has recommended utilizing the N0(i+) terminology for this finding, without impact in the final tumor stage. We performed a comparative retrospective multi-institutional survival analysis of 247 patients with endometrial carcinoma with regional lymph node metastasis of various sizes identified in nonsentinel lymphadenectomy, demonstrating that the cumulative survival of patients with isolated tumor cells in regional lymph nodes is not statistically different from patient with negative lymph nodes, and is statistically different from those with lymph nodes showing micrometastasis or larger metastatic deposits. In addition, we evaluated the prognostic implications of the number of involved regional lymph nodes, demonstrating a worsening prognosis as the number of involved lymph nodes increases from none to one, and from one to more than one. Our data suggests that regional lymph nodes with isolated tumor cells in patients with endometrial carcinoma should likely be considered, for staging purposes, as negative lymph nodes, simply indicating their presence with the (i+) terminology.

Beyond Sentinel Lymph Node: Outcomes of Indocyanine Green-Guided Pelvic Lymphadenectomy in Endometrial and Cervical Cancer

BACKGROUND

The aim of our study was to compare the number of lymph nodes removed during indocyanine green (ICG)-guided laparoscopic/robotic pelvic lymphadenectomy with standard systematic lymphadenectomy in endometrial cancer (EC) and cervical cancer (CC).

METHODS

This is a multicenter retrospective comparative study (Clinical Trial ID: NCT04246580; updated on 31 January 2023). Women affected by EC and CC who underwent laparoscopic/robotic systematic pelvic lymphadenectomy, with (cases) or without (controls) the use of ICG tracer injection within the uterine cervix, were included in the study.

RESULTS

The two groups were homogeneous for age (p = 0.08), Body Mass Index, International Federation of Gynaecology and Obstetrics (FIGO) stages (p = 0.41 for EC; p = 0.17 for CC), median estimated blood loss (p = 0.76), median operative time (p = 0.59), and perioperative complications (p = 0.66). Nevertheless, the number of lymph nodes retrieved during surgery was significantly higher (p = 0.005) in the ICG group (n = 18) compared with controls (n = 16).

CONCLUSIONS

The accurate and precise dissection achieved with the use of the ICG-guided procedure was associated with a higher number of lymph nodes removed in the case of systematic pelvic lymphadenectomy for EC and CC.

Sentinel lymphatic mapping for gynecologic malignancies

PURPOSE OF REVIEW

To summarize the latest data in Gynecologic Oncology for the use of sentinel lymphatic mapping in vulvar, uterine, and cervical cancers.

RECENT FINDINGS

To decrease morbidity and improve detection of lymphatic metastasis, lymphatic mapping with sentinel lymph node biopsy is emerging as standard of care over conventional systemic lymphadenectomy in the surgical management of gynecologic malignancies.

SUMMARY

Sentinel lymph node mapping with biopsy is one of the most significant advances in cancer surgery. The presence of nodal metastasis is not only a prognostic factor for recurrence and survival in patients with gynecologic malignancies, but also guides assessment for adjuvant treatment. This review article discusses the most recent clinical updates in sentinel lymph node mapping, dissection, and management in vulvar cancer, endometrial cancer, and cervical cancer.

A comparison of ICG-NIR with blue dye and technetium for the detection of sentinel lymph nodes in vulvar cancer

INTRODUCTION

The sentinel lymph node (SLN) procedure for vulva cancer is a safe alternative to a radical inguino-femoral lymphadenectomy (IFLN) for small unifocal tumours. SLN evaluation through biopsy and ultra-staging has helped gynaecological oncology surgeons improve operative morbidity with no cost to oncologic safety. Established techniques for groin SLN detection and excision in vulvar cancer use ^99mTc-nanocolloid radiotracer and blue dye (BD) for identification of the SLN. Indocyanine green (ICG)-near infrared (ICG-NIR) techniques for SLN mapping have proven utility in other gynaecological cancer sites and is gaining interest as a technique for SLN mapping in vulvar cancer METHODS: Fifty consecutive patients with unifocal vulvar squamous cell cancers of <40 mm lateral diameter and with depth of invasion > 1 mm underwent SLN mapping and excision using a combination of ^99mTc-nanocolloid, BD and ICG. SLN detection results were recorded on a per-patient and per-groin basis. The success rates SLN for detection by individual tracer substance or combinations of tracer were determined by presence of one or more tracer, detectable in the SLN specimen.

RESULTS

92% of patients had a successful SLN procedure. The per-groin detection rate was 84%. All successfully mapped SLN were identified with the combination of ICG-NIR and ^99mTc-nanocolloid compared to 69% with BD ^99mTc-nanocolloid. Success rates for the SLN procedure were not dependent on prior excision of the primary lesion or operator experience.

CONCLUSIONS

Incorporation of ICG-NIR into standard SLN mapping protocols may allow for the abandonment of routine use of BD and its poor side effect profile.

Association Study between the Sentinel Lymph Node Biopsy and the Clinicopathological Features of Patients with Cervical Cancer

Objective

The incidence of cervical cancer is increasing year by year, which seriously threatens the health of female patients. This study is aimed at investigating the association of sentinel lymph node biopsy (SLNB) with clinicopathological features in cervical cancer patients.

Methods

Patients diagnosed with cervical cancer in our hospital from February 1, 2019, to June 30, 2021, were selected as the research subjects. Statistical analysis was performed on the SLN examination of patients with cervical cancer with different pathological characteristics and the correlation between the positive rate of SLN detection and the pathological characteristics of cervical cancer.

Results

A total of 59 patients with cervical cancer were included in this study, the SLNB detection rate was 94.92%, 15 patients had lymph node metastasis, and the metastasis rate was 25.42% confirmed by histopathology. Thirteen of them had SLN metastases, and the other 2 had non-SLN metastases. The sensitivity of SLNB was 86.67%, and the false negative rate was 13.33%. Statistical analysis results showed that there was no significant difference in the positive rate of SLN among cervical cancer patients with different FIGO stages, pathological types, degree of differentiation, depth of invasion, and tumor size. In addition, the results of Pearson's correlation analysis showed that the positive rate of SLN was not significantly correlated with the FIGO stage, pathological type, degree of differentiation, depth of invasion, and tumor size of cervical cancer.

Conclusion

SLNB has a high sensitivity, safety, and feasibility in the diagnosis and evaluation of lymph node metastasis in cervical cancer. There is no significant correlation between SLNB and the clinicopathological features of cervical cancer.

Pathological processing of sentinel lymph nodes in endometrial carcinoma - routine aspects of grossing, ultra-staging, and surgico-pathological parameters in a series of 833 lymph nodes

Sentinel lymph nodes are widely accepted in the treatment of endometrial carcinoma. Whereas surgical aspects are well studied, the pathological work-up in terms of grossing, frozen section, and the so-called ultra-staging is still a matter of debate. This results in conflicting national or center-based recommendations. In a series of consecutive 833 sentinel lymph nodes from 206 patients in endometrial carcinomas, we compared three different grossing techniques and the use of frozen section in terms of anatomy, detection rates, and survival. In total, 42 macro-metastases, 6 micro-metastases, and 25 nodes with isolated tumor cells were found. Lymph nodes affected at least with micro-metastasis were about 0.5cm enlarged. Detection rates in lamellation technique increased with a step of 5.9% to 8.3% in comparison to bi-valved or complete embedding. The lamellation technique presented with a slight beneficial prognosis in pN0 subgroup (OS, p=0.05), which besides size effects might be attributed to trimming loss. In frozen section, this effect was less pronounced than expected (OS, p=0.56). Ultra-staging only revealed additional micro-metastases and isolated tumor cells. Exclusively, macro-metastases showed poor survival (p<0.001). In multivariate analysis, T-stage, subtype, and lympho-vascular invasion status outperformed this staging parameter significantly. Grossing of sentinel lymph nodes is the most essential step with evidence to prefer lamellation in 2 mm steps. Step sectioning should consider widely spaced protocols to exclude macro-metastases. Frozen sections might add value to the intra-operative assessment of endometrial carcinoma in selected cases. The excellent biological behavior of cases with isolated tumor cells might question the routine application of pan-cytokeratin as ultra-staging method.

Sentinel Lymph Node Mapping: Current Applications and Future Perspectives in Gynecology Malignant Tumors

The sentinel lymph nodes (SLNs) is a group of lymph nodes initially involved in the metastatic spread of cancer cells. SLN mapping refers to intraoperative localization and biopsy of SLNs with specific tracers to assess lymph node metastases. It is widely used in a variety of tumor surgeries for its high sensitivity and high negative predictive value. In the evaluation of the status of lymph node metastases in gynecological malignancies, it has received increasingly more attention due to its minor invasiveness, few complications, and high diagnosis rate. The National Comprehensive Cancer Network (NCCN) guidelines provide an excellent introduction to the indications and methods of SLN techniques in vulvar, cervical, and endometrial cancers, but they provide little explanation about some specific issues. In this review, we summarize different dyes and injection methods and discuss the indications of application and the clinical trials of SLN mapping in gynecological malignant tumors, aiming to provide a reference for the rational application of sentinel techniques in gynecology malignant tumors before relevant guidelines are updated.

Identification and Biopsy of Sentinel Lymph Node in Early-Stage Cervical Carcinoma: Diagnostic Accuracy and Clinical Utility

Background Due to the subsequent complications of pelvic lymphadenectomy in patients with early-stage cervical cancer, the sentinel lymph node (SLN) technique has been increasingly employed. This study aimed to investigate the detectability of SLN using methylene blue and explore the diagnostic accuracy of SLN biopsy. Methodology A study was conducted from September 2015 to August 2018 and included 90 women with cervical cancer, FIGO (International Federation of Gynecology and Obstetrics-2009) stage IA1-IIA1. Methylene blue was injected intracervically. Any detected dyed nodes were sent for frozen section biopsy, followed by bilateral pelvic lymphadenectomy. The predictive ability of SLN was evaluated in statistical terms after comparison of intraoperative biopsy and final histopathology. Results The sensitivity, specificity, false-negative rate, positive predictive value, and negative predictive value (NPV) were 55.6%, 95.1%, 4.9%, 55.6%, and 95.1%, respectively. The SLN performance in patients with tumor size ≤2.2 cm, negative lymphovascular space involvement, and depth of stromal invasion ≤5 mm was superior (sensitivity 100%, specificity 93.5%, NPV 100%). Conclusions The SLN technique with blue dye alone is a feasible and adequate alternative to systematic lymphadenectomy in early-stage cervical cancer in selected patients, given that a strict algorithm is applied.

Application of Single-Hole Laparoscopy and Sentinel Lymph Node Imaging in Early Endometrial Carcinoma in Special Population

AIM

To explore the clinical efficacy of single-hole laparoscopy combined with sentinel lymph node imaging in the treatment of early endometrial carcinoma in a special population.

METHOD

A retrospective analysis was made on the clinicopathological data of 8 patients with early endometrial carcinoma who underwent extra fascial total hysterectomy plus double adnexal resection and pelvic sentinel lymphadenectomy by transumbilical single-hole laparoscopy in Jiaxing Maternal and Child Health Hospital from Apr. 2019 to Apr. 2021.

RESULT

Single-hole laparoscopy and sentinel lymph node imaging were successfully performed in 8 patients with early endometrial carcinoma, and none of them was converted to porous or laparotomy. At the same time, all 8 patients have a high demand for body shape. All FIGO pathological grades were grade I before operation. Operation time is 160.87 ± 40.61 min, amount of bleeding is 68.75 ± 12.31 ml, the catheter was removed for 2 days, anal exhaust time is 30.13 ± 10.99 h, and postoperative hospital stay is 4.00 ± 1.07 d. There was no related organ injury during the operation, no case of blood transfusion, or case of poor wound healing. The evaluation of postoperative satisfaction was very satisfactory.

CONCLUSION

The application of single-hole laparoscopy and sentinel lymph node imaging in the treatment of early endometrial carcinoma in the special population should be safe and feasible with high satisfaction.

[Sentinel lymph node biopsy in the management of early-stage ovarian cancer: A systematic review of the literature]

The initial management of early-stage ovarian cancer consists of staging surgery including pelvic and para-aortic lymphadenectomy. The use of the sentinel lymph node (SLN) procedure in this setting may decrease the morbidity associated with this surgery. The objective of this review was to evaluate the feasibility of the SLN procedure in ovarian cancer diagnosed at an early stage by comparing the different techniques used and their accuracy. A systematic literature search was performed on PubMed and ClinicalTrials.gov for articles in English or French about the SLN technique in ovarian cancer. Ten studies were included in the analysis, with a total of 179 patients. The main tracers used were Technetium-99m, indocyanine green, and patent blue, and the most common site of injection was the proper ovarian and unfundibulopelvic ligaments. The overall detection rate was 87.7%. Of the small number of cases of lymph node metastasis reported, the SLN procedure had a sensitivity of 90.9% and a negative predictive value of 98.8%. The sentinel node procedure appears to be feasible and safe and could be reliable in determining the lymph node status of patients with early-stage ovarian cancer.

One-Step Nucleic Acid Amplification (OSNA) of Sentinel Lymph Node in Early-Stage Endometrial Cancer: Spanish Multicenter Study (ENDO-OSNA)

The objective of this study was to evaluate the efficacy of one-step nucleic acid amplification (OSNA) for the detection of sentinel lymph node (SLN) metastasis compared to standard pathological ultrastaging in patients with early-stage endometrial cancer (EC). A total of 526 SLNs from 191 patients with EC were included in the study, and 379 SLNs (147 patients) were evaluated by both methods, OSNA and standard pathological ultrastaging. The central 1 mm portion of each lymph node was subjected to semi-serial sectioning at 200 μm intervals and examined by hematoxylin-eosin and immunohistochemistry with CK19; the remaining tissue was analyzed by OSNA for CK19 mRNA. The OSNA assay detected metastases in 19.7% of patients (14.9% micrometastasis and 4.8% macrometastasis), whereas pathological ultrastaging detected metastasis in 8.8% of patients (3.4% micrometastasis and 5.4% macrometastasis). Using the established cut-off value for detecting SLN metastasis by OSNA in EC (250 copies/μL), the sensitivity of the OSNA assay was 92%, specificity was 82%, diagnostic accuracy was 83%, and the negative predictive value was 99%. Discordant results between both methods were recorded in 20 patients (13.6%). OSNA resulted in an upstaging in 12 patients (8.2%). OSNA could aid in the identification of patients requiring adjuvant treatment at the time of diagnosis.

Survival impact of number of removed para-aortic lymph nodes in stage I epithelial ovarian cancer

PURPOSE

The survival effect of presence or absence of lymphadenectomy in early-stage epithelial ovarian cancer (EOC) was priorly shown but the effect of number of removed lymph nodes kept in background. We aimed to evaluate the survival impact of number of removed lymph nodes and their localizations in stage I EOC.

METHODS

This study included 182 patients. The best cut-off levels for number of pelvic and para-aortic lymph nodes (PaLN) were 24 and 10, respectively. Univariate and multivariate survival analyses were performed for these cut-offs and other prognostic factors.

RESULTS

The median age of the patients was 49. The median number of removed pelvic and paraartic lymph nodes were 29 and 9, respectively. The median overall (OS) and progression-free survival (PFS) were 67 and 50 months, respectively. The 5-year OS rate was 89.6%. Recurrence occured in 24 (19.5%) patients. In univariate analyses tumor grade (p: 0.005), pelvic LN number (p: 0.041) and PaLN number (p: 0.004) were the factors that were significantly associated with PFS. Tumor grade and PaLN number were independently and significantly associated with PFS in multivariate analyses (p: 0.015 and p: 0.017, respectively). In OS analyses, age, tumor grade, presence of LVI, number of pelvic and PaLNs were the significantly associated factors (p < 0.05 for all). In multivariate analyses, age and PaLN number were independently and significantly associated with OS (p: 0.011 and p: 0.021, respectively).

CONCLUSIONS

The number and localizations of removed lymph nodes may have a survival affect in stage I EOC. We also think that this study may constitute a kernel point for larger prospective series on lymph node number and lymphatic regions.

[Reporting and handling of lymphonodectomy specimens in gynecologic malignancies and sentinel lymph nodes]

Die Aufarbeitung von Lymphonodektomiepräparaten gynäkologischer Malignome orientiert sich an den nationalen AWMF-Leitlinien und internationalen Empfehlungen. Die Definition von Mikrometastasen und isolierten Tumorzellen entspricht den Festlegungen der UICC(Union Internationale Contre le Cancer)/TNM(TNM-Klassifikation maligner Tumoren). Deren Nachweis soll im Befundbericht erwähnt werden sowie in die Tumorklassifikation einfließen. Alle übersandten Lymphknoten (LK) sollen untersucht werden mit vollständiger Einbettung aller LK bis 0,3 cm und Lamellierung aller größeren Lymphknoten parallel zu ihrer kurzen Achse in ca. 0,2 cm dicken Scheiben. Bestandteile des histologischen Befundberichtes sind: Zahl der befallenen LK im Verhältnis zur Zahl der entfernten/untersuchten LK entsprechend der Entnahmelokalisationen, metrische Ausdehnung der größten LK-Metastase, Fehlen/Nachweis einer extrakapsulären Ausbreitung. Zuschnitt und Einbettung von Sentinel-LK mit oder ohne Schnellschnittuntersuchung erfolgt in Analogie zu Nicht-Sentinel-LK mit Anfertigung von ca. 3 HE-gefärbten Stufenschnitten in einem Abstand von ca. 200 µm sowohl vom Gefrier- als auch Paraffinblock. Stellen sich die Sentinel-LK in der HE-Färbung negativ dar, soll ein immunhistochemisches Ultrastaging erfolgen.

Operative and Oncological Outcomes Comparing Sentinel Node Mapping and Systematic Lymphadenectomy in Endometrial Cancer Staging: Meta-Analysis With Trial Sequential Analysis

Objective

To evaluate the utility of sentinel lymph node mapping (SLN) in endometrial cancer (EC) patients in comparison with lymphadenectomy (LND).

Methods

Comprehensive search was performed in MEDLINE, EMBASE, CENTRAL, OVID, Web of science databases, and three clinical trials registration websites, from the database inception to September 2020. The primary outcomes covered operative outcomes, nodal assessment, and oncological outcomes. Software Revman 5.3 was used. Trial sequential analysis (TSA) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) were performed.

Results

Overall, 5,820 EC patients from 15 studies were pooled in the meta-analysis: SLN group (N = 2,152, 37.0%), LND group (N = 3,668, 63.0%). In meta-analysis of blood loss, SLN offered advantage over LND in reducing operation bleeding (I² = 74%, P<0.01). Z-curve of blood loss crossed trial sequential monitoring boundaries though did not reach TSA sample size. There was no difference between SLN and LND in intra-operative complications (I² = 7%, P = 0.12). SLN was superior to LND in detecting positive pelvic nodes (P-LN) (I² = 36%, P<0.001), even in high risk patients (I² = 36%, P = 0.001). While no difference was observed in detection of positive para-aortic nodes (PA-LN) (I² = 47%, P = 0.76), even in high risk patients (I² = 62%, P = 0.34). Analysis showed no difference between two groups in the number of resected pelvic nodes (I² = 99%, P = 0.26). SLN was not associated with a statistically significant overall survival (I² = 79%, P = 0.94). There was no difference in progression-free survival between SLN and LND (I² = 52%, P = 0.31). No difference was observed in recurrence. Based on the GRADE assessment, we considered the quality of current evidence to be moderate for P-LN biopsy, low for items like blood loss, PA-LN positive.

Conclusion

The present meta-analysis underlines that SLN is capable of reducing blood loss during operation in regardless of surgical approach with firm evidence from TSA. SLN mapping is more targeted for less node dissection and more detection of positive lymph nodes even in high risk patients with conclusive evidence from TSA. Utility of SLN yields no survival detriment in EC patients.

Long-term outcomes of individualized management after sentinel lymph-node biopsy for vulvar cancer

BACKGROUND

The management for patients with vulvar cancer after sentinel lymph-node biopsy (SLNB) remains controversial. The aim of this study was to investigate the long-term outcomes of individualized management after SLNB for early stage vulvar cancer.

METHODS

The medical records of patients with vulvar cancer treated by surgery involving SLNB between 2004 and 2019 were retrospectively reviewed. During this period, the inguinofemoral lymphadenectomy (IL) were performed with individualized strategy, while the postoperative intensity-modulated radiotherapy was planned with a consistent policy.

RESULTS

We identified 138 patients with at least one sentinel node detected, of whom 64 underwent further IL while 74 had SLNB only. Nodal metastases (pN+) were confirmed in 22 patients with IL and 16 without. Radiotherapy was scheduled with the dose of 60-70 Gy for all pN+ patients and finally completed in 15 with IL and 15 without. The median follow-up time was 56 months (6-156 months). Recurrence was observed in 24 patients, of whom 10 were pN- at primary treatment. The 3-year overall survival (OS) was 97.2, 95.2, 68.3, and 71.8%; 3-year disease-free survival (DFS) was 94.5, 91.4, 60.2, and 59.2%, respectively, for patients with pN- and IL, pN- and SLNB, pN+ and IL, and pN+ and SLNB. Neither OS nor DFS showed significant difference between SLNB and IL in pN- (P = 0.564 for OS, P = 0.423 for DFS), or pN + patients (P = 0.920 for OS, P = 0.862 for DFS).

CONCLUSIONS

With appropriate adjuvant radiotherapy, SLNB alone provided similar long-term survival compared with IL for both patients with and without sentinel node metastasis.

Status of Sentinel Lymph Node Biopsy in Vulvar and Cervical Cancer

Assessment of lymphatic metastasis is an essential component of solid tumour staging. Sentinel lymph node (SLN) biopsy is a minimally invasive procedure that allows regional lymph node involvement by tumour to be estimated by selectively examining the sentinel lymph node while minimising the morbidity of systematic lymph node dissection. Within the group of genital cancers, the diagnostic value of SLN biopsy is rated differently. For selected patients with early-stage vulvar cancer (unifocal primary tumour < 4 cm, clinically negative inguinal lymph nodes) the SLN technique is already an established procedure in the guidelines of the German Society for Gynaecology and Obstetrics (DGGG)/German Cancer Society (DKG) and the recommendations of the European Society of Gynaecological Oncology (ESGO). For cervical cancer, SLN biopsy has not yet been sufficiently standardised but can be considered for patients without risk factors with a primary tumour size < 2 cm. The SLN is identified by combined use of radioactive ^99m technetium nanocolloid and patent blue. The use of indocyanine green offers an alternative for SLN identification with few side effects. Recent studies aim to increase the diagnostic reliability of intraoperative frozen section analysis as this continues to show limited sensitivity in both vulvar and cervical cancer. The rate of detection of micrometastases can be increased by additional ultrastaging, the prognostic significance of which for both diseases is still unclear. The prognostic value of SLN biopsy compared with systematic lymph node dissection is being investigated in current studies (GROINSS-V-II for vulvar cancer and SENTIX-, SENTICOL-3 for cervical cancer). For this review article, a guideline-based literature search was performed in the National Library of Medicine (PubMed/MEDLINE) database with a particular focus on recent cohort studies and conference contributions.

Standard ultrastaging compared to one-step nucleic acid amplification (OSNA) for the detection of sentinel lymph node metastases in early stage cervical cancer

OBJECTIVE

We compared ultrastaging and one-step nucleic acid amplification (OSNA) examination of sentinel lymph nodes in two homogeneous patient populations diagnosed with early stage cervical cancer. The primary aim of our study was to evaluate the rate and type of sentinel lymph node metastases detected by ultrastaging and OSNA assay. Secondary aims were to define the sensitivity and the negative predictive value of sentinel lymph node biopsy assessed with OSNA and ultrastaging and to define the role of sentinel lymph node assessment in predicting non-sentinel lymph node status.

METHODS

Consecutive patients who underwent surgery (radical hysterectomy or trachelectomy or cervical conization) at our institution, between January 2018 and March 2020, were enrolled. All patients had a preoperative diagnosis of early-stage cervical carcinoma (International Federation of Gynecology and Obstetrics (FIGO) 2018 stages IA-IIB) and underwent sentinel lymph node assessment with ultrastaging or OSNA. Patients with advanced FIGO stages and special histology subtypes (other than squamous cell carcinoma, adenocarcinoma or adenosquamous carcinoma) or patients with sentinel lymph nodes analyzed only with hematoxylin and eosin were excluded. Clinical data were compared using the χ² test and Fisher's exact test. A κ coefficient was determined with respect to lymph node assessment. A p value <0.05 was considered statistically significant.

RESULTS

A total of 116 patients were included in this retrospective analysis (53 ultrastaging, 63 OSNA). Overall, 531 and 605 lymph nodes were removed in the ultrastaging and OSNA groups, respectively, and 140 and 129 sentinel lymph nodes were analyzed in the ultrastaging and OSNA groups, respectively. 22 patients had metastatic sentinel lymph nodes: 6 (11.3%) of 53 patients in the ultrastaging group and 16 (25.4%) of 63 patients in the OSNA group. The total amount of positive SLNs was 7 (5%) of 140 in the ultrastaging group and 21 (16.3%) of 129 in the OSNA group, respectively (p=0.0047). Pelvic lymphadenectomy was performed in 26 (49.1%) of 53 patients in the ultrastaging group and in 34 (54%) of 63 patients in the OSNA group due to comorbidities. Metastatic non-sentinel lymph nodes were found in 4 patients: 2 (7.7%) of 26 patients in the ultrastaging group and 2 (5.9%) of 34 patients in the OSNA group, respectively. The total amount of positive pelvic lymph nodes was 3 (0.6%) of 531 in the ultrastaging group and 4 (0.7%) of 605 in the OSNA group (p=0.61). In the OSNA group, only 2 patients with negative sentinel lymph nodes had metastatic disease in the pelvic lymph nodes. By contrast, no patients with OSNA-positive sentinel lymph nodes had metastases in the pelvic lymph nodes. In the ultrastaging group, all patients with negative sentinel lymph nodes did not have metastatic disease in other pelvic lymph nodes.

CONCLUSIONS

OSNA assessment of sentinel lymph nodes was associated with a negative predictive value of 91% but poor reliability in detecting node metastases in non-sentinel pelvic lymph nodes. Of note, the ultrastaging protocol revealed higher sensitivity and more reliability in predicting pelvic non-sentinel lymph node status.

Highlighted issues from the second edition RCPA Endometrial Cancer Structured Reporting Protocol

Endometrial cancer is the most common malignancy of the female genital tract in the Western world. The second edition Endometrial Cancer Structured Reporting Protocol was published to the Royal College of Pathologists of Australasia (RCPA) website in December 2019, and relates to the reporting of endometrial cancer in hysterectomy specimens. This editorial discusses selected key issues from the second edition of the RCPA protocol, and addresses future challenges in pathology reporting of endometrial cancer.

Pathology of sentinel lymph nodes: historical perspective and current applications in gynecologic cancer

Efforts to reduce surgical morbidity related to en bloc lymph node removal associated with cancer surgery led to the development of targeted lymph node sampling to identify the lymph node(s) most likely to harbor a metastasis. Through identification of one or only a few lymph nodes at highest risk, the overall number of lymph nodes removed could be markedly reduced. Submission of fewer lymph nodes affords more detailed pathologic examination than would otherwise be practical with a standard lymph node dissection. Such enhanced pathologic examination techniques (ie, ultra-staging) have contributed to increased detection of lymph node metastases, primarily by detection of low volume metastatic disease. Based on the success of sentinel lymph node mapping and ultra-staging in breast cancer and melanoma, such techniques are increasingly used for other organ systems including the gynecologic tract. This review addresses the historical aspects of sentinel lymph node evaluation and reviews current ultra-staging protocols as well as the implications associated with increased detection of low volume metastases.